“I would like to know if I am related to a president of Mexico. The story told to me was that Jesús Carranza, described as ‘former president of Mexico,’ was assassinated by rebels, and his children had to flee the country as a result. (Jesús was actually the father of Venustiano Carranza, who himself became president of Mexico in 1917.) Family lore continues that one of Jesús’ sons came to America and had a daughter (my grandmother Margaret Carranza) with my great-grandmother Effie Mae Taylor. I believe my grandmother’s birth certificate does say that a Jesús Carranza is the father, though I do not have a copy to send.

“But the plot gets thicker. Apparently Jesús Carranza’s brother married my great-grandmother’s sister Victoria Furnell or Fennell. (She eventually had several last names due to multiple marriages, I’m told.) So essentially there were two brothers married to two sisters. According to my dad, the sisters’ mother, Margaret Dunsmore, grew up on an Indian reservation in Oklahoma. (He thinks she was Native American, but you know all black folks claim this.)

“This was the story that was told to me by my great-grandmother Effie Mae, who died in Chicago in 2006 at the age of 99. I have enclosed additional information to aid the search.”—Toya Menzie

Using the information you have obtained thus far on your great-grandmother, her sister and their mother, we recommend beginning your search by reviewing the Social Security Death Index. This database is available online through Ancestry.com and other sources.

The index will help you determine the exact birth and death dates of these individuals, as well as their birthplaces and residences at the time of death. Once you have obtained this information, try searching for their death records in the counties where they died in order to help establish the connection between the siblings as well as with the parents.

Obituaries and death notices are another valuable resource for learning more about family members. Several online subscription newspaper databases, including GenealogyBankand NewspaperArchive.com, will allow you to search by name, state and date. Another option is to contact the city or county library where a relative resided prior to her death. A number of libraries have older newspapers available on microfilm and can provide assistance in searching for a death notice or obituary. Since you told us that your great-grandmother’s sister Victoria was married several times, she may be listed under different surnames in her sister’s and mother’s obituaries, which will help you establish a general time frame of when she remarried.

You also note that it is believed Margaret Dunsmore grew up on an Indian reservation in Oklahoma. If you are able to locate her death record, you can use the information on that document as a starting point for tracing her line back another generation. Depending on the informant for this record, you may be able to learn the names of her parents and establish whether she was born in Oklahoma.

With this information, you can conduct a search of census records to determine where her family resided when she was a child. Her siblings may be listed on her death notice or obituary, which will enable you to determine whether a particular family in the census is a match to Margaret Dunsmore’s family. Based on her family’s location in these census records, you can check the local and county historical society for other sources that may help you learn more about her family’s origins.

Regarding the Carranza family, we recommend that you search online for biographies on this family, as well as books on the history of Mexico. Another valuable online resource is the Historical Text Archive, which has in its collection the article “Venustiano Carranza, Liberal Mexican Political Leader (1859-1920).” According to this article, Venustiano Carranza had 14 siblings. A number of Mexico’s civil and church records are available online at FamilySearch, which can help you determine whether any of the male lines in the Carranza family are connected to Effie Mae Taylor.

Although family lore is that one of Jesús Carranza’s sons married Effie May Taylor, keep in mind that Jesús Carranza Neira, whose son was Venustiano, was born in 1813 and Effie May Taylor was born in 1906, which would make this Jesús Carranza’s son significantly older than Effie at the time of their marriage. It is possible that Effie married a grandson of Jesús Carranza rather than one of his sons—in fact, one of Jesús Carranza Neira’s sons was named Jesús Carranza Garza—so be sure to extend your research to grandchildren in the event that Effie married into the Carranza family through a different generation. But first be sure to check your grandmother’s birth certificate for the information on her father.

Finally, we encourage you to take a test to analyze your autosomal DNA. This will reveal your percentages of various geographical ancestries, including Native American, sub-Saharan African, European and, within European, various subregions. Mexicans, on average, have much higher percentages of Native American ancestry than either white or black Americans. A high percentage of Native American ancestry would tend to confirm the stories passed down in your family, or at least suggest that someone from Mexico, even if not a president or his descendant, is on your family tree!

Henry Louis Gates Jr. is the Alphonse Fletcher University Professor and founding director of the Hutchins Center for African and African American Research at Harvard University. He is also the editor-in-chief of The Root. Follow him on Twitter and Facebook.

This answer was provided in consultation with Eileen Pironti, a researchers from the New England Historic Genealogical Society. Founded in 1845, NEHGS is the country’s leading nonprofit resource for family history research. Its website, AmericanAncestors.org, contains more than 300 million searchable records for research in New England, New York and beyond. With the leading experts in the field, NEHGS staff can provide assistance and guidance for questions in most research areas. They can also be hired to conduct research on your family. Learn more today.